Abstract:
In order to investigate the vertical distribution of soil available boron and available molybdenum content in paddy-tobacco growing areas of Hunan Province, in 2017, 150 soil samples with 0-50 cm profile in Chenzhou, Hengyang and Changsha tobacco growing areas were collected. The vertical distribution characteristics of available boron and available molybdenum in tobacco planting soil were analyzed by multivariate statistical method, and the relationship between them and organic matter was studied. The contents of available boron and molybdenum in soil decreased with the deepening of soil layer. The available boron content of 20-50 cm soil layer in Chenzhou and Hengyang tobacco area was "low", and that in Changsha tobacco area was "very low". In Chenzhou and Hengyang tobacco areas, the available molybdenum content of each soil layer is "medium" or "rich", while in Changsha tobacco area, the available molybdenum content of 30-50 cm soil layer is "low". There was a significant positive correlation between the content of soil available boron and available molybdenum and the content of organic matter, and the content of available boron and organic matter in each soil layer was consistent with the linear model. The contents of available molybdenum and organic matter were consistent with the linear model in 0-30 cm soil layer, and in line with the linear plus platform model in the 30-50 cm soil layer. With the increase of soil depth, the correlation between organic matter and available boron was strengthened, and the correlation between organic matter and available molybdenum was weakened. Under the long-term small-scale mechanical and artificial farming system, with the soil tillage layer becoming shallower, the available boron and available molybdenum showed a trend of surface enrichment.